[RFI] Splatter from AM Radio Station WNTS Indianapolis

[Gary Peterson]

Don,

This could be one of the rare instances that a sudden change occurred in the radio station’s transmitting system.  Rare, but not unheard of. 

I find it interesting that you mentioned that the station’s output power far exceeded measurements, made 2 weeks prior, during the annual inspection.  Is it possible that the station was running at some level of reduced power at the time that the NRSC 2 measurements were performed?  Before I measure any AM station, I ensure that the station is operating at licensed power.  I either talk directly to their engineer, check their remote control readings or actually enter the transmitter building.  Once, I found an AM station running night power during the day.  Apparently, a power bump killed the clock in the remote control system.  The UPS battery had failed, causing the clock to zero the date and time.  This probably happened at night and left the station stalled on night power.  Just a couple of months ago, I measured a local AM station that was not in compliance with occupied bandwidth measurements.  I checked the same station at night, to see if the problem existed when they should have been at night, reduced power.  They were at full power, two hours after local sunset.  Same situation.  Power bump with failed UPS resulting in station staying at full power, 24 hours per day.  Who knows how long this had been going on.

I never cease to be surprised at what I sometimes encounter.  My favorite saying about many broadcast stations is that the lights may be on, but nobody’s home.

Gary
KzeroCX


Funny that you bring this up (annual inspection).  It just so happens that WNTS had just gone through their annual inspection (measurements) 2 weeks prior to the splatter showing up and I saw the paper work documenting the inspection, and I know for a fact that I could not hear the splatter 10 days prior to the splatter occurring when I was down in the area of the transmitter site and when I heard the splatter 10 days later it was very strong.  We also noticed something odd when I went to the transmitter site with their engineers to determine the problem as the transmitter output power far exceeded the measurements that were made 2 weeks prior during the annual inspection so it did indeed appear the issue was not a gradual issue, but more of a sudden failure.

Just FYI,
Don (wd8dsb)